MOLECULAR REGULATION OF IMMUNOGLOBULIN GENE EXPRESSION

这里提出的实验涉及到基因和基因之间的关系 影响免疫球蛋白重的组织和基因表达 小鼠链(IgH)基因家族及其邻近基因和基因家族 12号染色体。构建详细的连锁和物理图谱 染色体，从种间分离的染色体特异DNA片段 体细胞杂交将被用来定义限制片段长度 并对携带亚染色体片段的杂交种进行分析。 染色体“跳跃”程序将被用来描述该区域 原癌基因c-fos和IgH之间的关系。从转录上辨认 染色体上的活性位点，差异杂交技术将是 用于分离特定于染色体、特定于组织的cDNA。这个 这些在免疫系统发育过程中的表达将是 采用原位杂交方法进行分析。确定…的结构基础 在之前的实验中发现的广泛的DNA水平的多态，等位基因 这些基因座的形式将被克隆并通过限制性内切酶图谱进行研究， 异源双链分析，并在必要时进行序列分析，以便 确定特定类别的事件(换位， 非同源重组)是造成观察到的多样性的原因。 除了这些实验应该提供的对基因的洞察之外 小鼠12号染色体的组织及其功能后果 组织，工作应有助于更广泛地确定战略 哺乳动物基因组织的“中级”分析。

The experiments proposed here concern the relationship between gene organization and gene expression as it affects the immunoglobulin heavy chain (Igh) gene family, and neighboring genes and gene families on mouse chromosome 12. To construct detailed linkage and physical maps of the chromosome, chromosome-specific DNA fragments isolated from an interspecies somatic cell hybrid will be used to define restriction fragment length polymorphisms and to analyze hybrids carrying subchromosomal fragments. Chromosome "hopping" procedures will be used to characterize the region between the proto-oncogene c-Fos and Igh. To identify transcriptionally active loci in the chromosome, difference hybridization techniques will be used to isolate chromosome-specific, tisssue-specific cDNAs. The expression of these during the development of the immune system will be analyzed by in situ hybridization. To determine the structural basis of the extensive DNA-level polymorphism found in previous experiments, allelic forms of these loci will be cloned and studied by restriction mapping, heteroduplex analysis, and, where necessary, sequence analysis, in order to determine whether particular classes of events (transpositions, non-homologous recombinations) are responsible for the observed diversity. Beyond the insight that these experiments should provide into the genetic organization of mouse chromosome 12 and functional consequences of that organization, the work should help to define strategies more generally for the "mid-level" analysis of mammalian gene organization.